Dry Mouth and Bad Breath: Causes and Care

What saliva does

Saliva rinses debris, neutralises acid, supplies minerals that repair early enamel damage, carries antimicrobial components, and makes speaking, tasting and swallowing possible.

Reduced flow therefore raises the risk of decay — often rapidly and at the gumline — as well as causing soreness, altered taste, difficulty with dentures and bad breath.

Common causes of dry mouth

Medication is the most frequent cause in adults.

• Many antidepressants, antihistamines, diuretics and blood pressure medications
• Medical conditions including diabetes and autoimmune conditions such as Sjogren syndrome
• Radiotherapy to the head and neck
• Dehydration, mouth breathing and sleeping with the mouth open
• Alcohol, caffeine and tobacco

Where bad breath comes from

Persistent bad breath most often originates in the mouth: bacterial coating on the back of the tongue, plaque and food retention between teeth, gum disease, dry mouth, or an infected tooth. Less commonly it relates to sinus, throat, gastrointestinal or metabolic causes.

Because the underlying source differs, mouthwash used alone tends to mask rather than resolve it.

Measures that generally help

Sip water regularly. Chew sugar-free gum, ideally containing xylitol, to stimulate flow. Limit alcohol, caffeine and tobacco. Consider a humidifier at night if you wake dry. Saliva substitutes and dry-mouth rinses are available over the counter.

For breath specifically: clean between the teeth daily, clean the tongue gently with a brush or scraper, keep dentures scrupulously clean and out overnight where advised, and treat any gum inflammation.

When to seek assessment

See a dentist if dry mouth persists, if breath does not improve with consistent hygiene, if new decay is appearing, or if there is soreness, ulceration or difficulty swallowing. Do not stop prescribed medication because of dry mouth — discuss it with the prescriber, who may be able to adjust it.